DuodenoscopyCrohn DiseaseAlzheimer DiseaseAmyloid beta-PeptidesAmyloid beta-Protein Precursortau ProteinsNeurofibrillary TanglesPlaque, AmyloidBrainApolipoprotein E4NeurofibrilsDementiaAmyloid Precursor Protein SecretasesPresenilin-1AmyloidCognition DisordersAtrophyNeuropsychological TestsDementia, VascularApolipoproteins EMild Cognitive ImpairmentPeptide FragmentsPresenilin-2HippocampusCognitionMental Status ScheduleAgingLewy Body DiseaseAspartic Acid EndopeptidasesNeuronsMagnetic Resonance ImagingMice, TransgenicAge of OnsetCholinesterase InhibitorsMemantinePresenilinsAniline CompoundsCerebral CortexMemory DisordersBrain ChemistryNational Institute on Aging (U.S.)Cerebral Amyloid AngiopathySubstantia InnominataAutopsyNerve DegenerationProtease NexinsLongitudinal StudiesDisease Models, AnimalDown SyndromeNeurodegenerative DiseasesTauopathiesAmyloidogenic ProteinsPhenylcarbamatesDisease ProgressionPositron-Emission TomographyIndans